Lessons In MSBuild - Targets Are Called Only Once

By design, targets in a MSBuild process are only called once. This is an important concept to understand, as it is unusual for the typical developer.

I had a situation where I wanted to call the same target from a few places in my MSBuild project - but I wanted to pass in different property values. I didn’t want to repeat myself (DRY principle).

If <CallTarget ...> is used then the target is only called once within that process.

I found a sneaky way to work around this by examining the file C:\Program Files\MSBuild\Microsoft\VisualStudio\TeamBuild\Microsoft.TeamFoundation.Build.targets.

Instead of using <CallTarget ...>, use <MSBuild ...> which spawns off a new MSBuild process, thus allowing the target to be called each time.

1<MSBuild Projects="$(MSBuildProjectFile)" Targets="MyTarget" Properties="MyProperty1=blah;MyProperty2=$(MyVariable)\blah2" />